Let 'ab' be the two digit number. Where b≠0. On interchanging the digits, the new number will be 'ba' As per the condition 10a+b>3×(10b+a) 7a>29b For b=1,a={5,6,7,8,9} For b=2,a={9} For b=3, no value of 'a' is possible. Hence, there are a total of 6 such numbers